Causes and Treatment of Psoriasis

Psoriasis cannot be cured, but there are treatment options that include biologic drugs, topicals, and light therapy.

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While the exact cause of psoriasis is unknown, it’s an autoimmune condition in which a faulty immune system changes the life cycle of skin cells in the body.1

This change causes the cells to build up rapidly on the surface of the skin in just a few days. (For those without psoriasis, this process usually takes about a month.)

These extra skin cells form thick, itchy, dry, red patches, called plaques, on the skin’s surface.

Is Psoriasis Contagious?

While more research is needed to fully understand psoriasis, we do know that the condition is not contagious.

In other words, you can’t spread the disease through touch, saliva, or during any kind of sexual contact.

Is Psoriasis Genetic?

In addition to your immune system, genetic factors have a lot to do with whether you’ll develop psoriasis.2

People who get psoriasis usually have one or more family members with the condition. But having family members with the disease does not mean you’ll definitely get it.

At least 10 percent of the general population inherits one or more of the genes that create a predisposition to psoriasis.

Despite this, only 2 to 3 percent of those people actually develop the disease, according to the National Psoriasis Foundation.3

The best explanation: The individuals who do get the disease have a certain combination or “mix” of genes and are exposed to environmental triggers — some of which are still unknown — that lead to the development of psoriasis.

What Are the Risk Factors for Psoriasis?

While anyone can develop psoriasis, the following factors can increase your risk:

Family History Having one parent with psoriasis increases your risk, and having two parents with the condition puts you at greater risk.

Infections People with HIV are more likely to develop psoriasis. Additionally, strep throat has been linked with the development of a certain type of psoriasis, called guttate psoriasis. This causes small round red scaly rashes to develop, usually on the trunk and arms. Kids and young adults with this type of recurring infection may be at increased risk.4

Stress Since stress can impact your immune system by causing inflammation, high stress levels may increase your risk of psoriasis.5

Obesity Being overweight or obese increases your risk, and psoriasis often develops in the creases and folds of skin.

Smoking Smoking tobacco increases your risk and the severity of psoriasis, and may initiate the development of the disease.6

How Is Psoriasis Treated?

Most psoriasis therapies aim to stop skin cells from growing so quickly, reduce inflammation, and smooth out the skin.

Proper psoriasis treatments can help clear the condition and improve your quality of life.

What works for one person might not work for another, so keep trying therapies until you find one that’s effective for you.

Doctors typically start with the mildest approach and move on from there.

Topical Treatments: Over-the-Counter and Prescription

Topical treatments are applied directly to the skin and are usually the first option for treating mild to moderate psoriasis.7

These therapies can be divided into two categories: over-the-counter (OTC) topicals and prescription topicals.

OTC Topicals

Salicylic Acid This medicine is a keratolytic (peeling agent) that causes shedding of the outer layer of your skin. Besides psoriasis, it is used to treat acne, dandruff, and seborrhea, and to remove corns, calluses, and warts. There are many forms and brands of topical salicylic acid on the market. Salicylic acid topical is available as an ointment, liquid, gel, soap or shampoo, cloth pads, sprays, and skin patches.8

Common side effects may include minor skin irritation, rash, and changes in the color of treated skin. The medicine can cause a rare allergic reaction, so you may choose to apply a small “test dose” initially to see how your skin responds. You should stop using salicylic acid topical and tell your doctor if you experience serious side effects, such as severe headache, stomach pain, or shortness of breath.

Coal Tar These topicals contain actual tar that comes from coal. Like salicylic acid, coal tar medication belongs to a class of drugs called keratolytics or keratoplastics. They are prescribed to relieve itchiness, dryness, and scaling caused by various skin conditions besides psoriasis, such as eczema and dermatitis. These drugs work by helping your skin shed dead cells from its top layer.8

Coal tar topicals come in various formulations and are considered one of the oldest psoriasis treatments. They are available as an ointment, liquid, cream, lotion, gel, soap, and shampoo. Your dose will depend on your condition and the type of coal tar you’re using.

Coal tar topicals will make your skin more sensitive to the sun, so use caution outdoors on days following your treatment. Tell your doctor if any of the following side effects become severe or persist: itching, burning, redness, or staining of your skin or hair Serious side effects may include signs of infection in or around the treated area, and signs of anaphylaxis, which may include rash, hives, difficulty breathing, chest tightness, or swelling of your face, mouth, lips, or tongue.

Others Topicals Additional OTC topical products that contain aloe vera, jojoba, urea, or zinc pyrithione can help moisturize and soothe the skin. Capsaicin, the active ingredient in chili peppers that makes them hot, is used in medicated creams and lotions to relieve muscle or joint pain, but its topical application may also be useful in the treatment of psoriasis.

Prescription Topicals

Nonsteroidal Topical medicines that do not contain steroids are often prescribed to control excessive skin cell production. Synthetic vitamin D3 is commonly used to slow down the growth of skin cells. It’s found in the medicines Vectical (calcitriol) and Dovonex (calcipotriene). Synthetic vitamin A is also given to help symptoms. The medicine Tazorac (tazarotene) contains a compound that’s similar to vitamin A. Another nonsteroidal topical is Zithranol (anthralin), which is a synthetic form of a substance found in the bark of the South American araroba tree.

Corticosteroids These anti-inflammatory medicines, generally referred to as steroids, are the most frequently used treatments for psoriasis. Topical steroids are made from the natural corticosteroid hormones produced by the adrenal glands. They come in various brands and strengths, depending on the specific condition.9

Long-term use of powerful steroids can cause thinning of the skin and treatment resistance, so your doctor will have to weigh the benefits and risks of prescribing this therapy. There is a low risk of the topical steroid causing systemic effects unless applied to the entire body at high strength.

Psoriasis Drugs: Biologic Medication

Biologic drugs are protein-based medicines that are derived from living cells cultured in a laboratory.8

These medicines are administered through an injection or IV and target parts of the immune system.

Biologics work by blocking the action of a specific type of immune cell and proteins in the immune system that play a major role in the development of psoriasis.

The following medicines are examples of biologics:

Cosentyx (secukinumab)

Enbrel (etanercept)

Humira (adalimumab)

Remicade (infliximab)

Siliq (brodalumab)

Stelara (ustekinumab)

Taltz (ixekizumab)

Tremfya (guselkumab)

Psoriasis Drugs: Systemic Medication

Systemic treatments for psoriasis are drugs that work throughout the body.

They’re usually used in people with moderate to severe psoriasis who don’t benefit from topical medicines or UV light therapy.

Systemic medicines can be taken by mouth or given by injection.

Traditional systemic drugs include:

Neoral (cyclosporine)

Trexall (methotrexate)

Otezla (apremilast)

Soriatane (acitretin)

Sometimes drugs can be given off label, which means your doctor will prescribe them even if they aren’t approved by the Food and Drug Administration (FDA) for your specific condition.

Examples of off-label systemic medicines for psoriasis include:

Hydrea (hydroxyurea)

6-thioguanine

Accutane (isotretinoin)

CellCept (mycophenolate mofetil)

Azulfidine (sulfasalazine)

How Does Light Therapy Work for Psoriasis?

Light therapy, also known as phototherapy, is a treatment that focuses specific types of light onto the skin.10

Your doctor may suggest one or more of the following phototherapy or combination therapy approaches:

Ultraviolet B (UVB) This is an effective choice and can be delivered as either broadband UVB (BB-UVB) or narrowband UVB (NB-UVB). UVB phototherapy is a good course of treatment for people with moderate to severe cases of psoriasis, patients with plaque psoriasis, those with thin plaques, and people who are generally responsive to natural sunlight.

PUVA (Psoralen and Ultraviolet A) For advanced cases of psoriasis, a physician might suggest combining exposure to ultraviolet A light with prescribing psoralen, a light-sensitizing medication that is most commonly administered orally. Taken shortly before light treatment, psoralen seems to boost the therapeutic effect of light on the immune system. People with moderate to severe cases of plaque psoriasis, guttate psoriasis, and psoriasis of the palms and soles are good candidates for PUVA.

The therapy is done in a doctor’s office, psoriasis clinic, or at home with a phototherapy unit. The FDA regulates medical devices used in the application of phototherapy. Laser treatments, using a device known as an excimer laser, can administer highly targeted beams of ultraviolet light to treat select areas of affected skin.

Before starting phototherapy, tell your doctor about any new drugs you are taking. Light therapy may not be recommended for people with certain medical conditions, such as lupus and porphyria, that require avoiding exposure to sunlight.

Patients undergoing phototherapy should pay special attention to their skin. Minor side effects can include redness and itching, and a patient’s psoriasis may worsen temporarily. Skin should also be monitored for suspicious lesions and any other early signs of cancer.

What Complementary and Alternative Treatments Help Psoriasis?

Complementary and alternative therapies are sometimes used to improve symptoms of psoriasis.

Although most of these approaches are safe, you should talk to your doctor before trying any new treatment or technique.

Examples of complementary and alternative methods commonly used to treat psoriasis include:

Diet and Nutrition Some people report improved symptoms by altering their diets or taking certain supplements. You can also try avoiding specific dietary triggers that may increase inflammation and worsen your symptoms.11

Sunlight Exposure to small amounts of sunlight can reduce some symptoms of psoriasis. But too much sun can worsen outbreaks and increase your risk of skin cancer. Talk to your doctor about how much sunlight exposure is safe for your situation.

Daily Baths Soaking in mineral water baths may help hydrate and soften the skin. You can add colloidal oatmeal, Epsom salts, or Dead Sea salts to bathwater to help calm inflamed skin. But stay away from hot water and harsh soaps, which can worsen your symptoms.

Moisturizer Some people report fewer symptoms when they apply moisturizer to affected areas. Ointments can help lock in moisture better than creams.

Yoga and Meditation These practices can clear your mind and reduce stress, which may ease symptoms of psoriasis.5

Exercise Physical activity increases the production of chemicals known as endorphins, which improve mood and energy. Exercise can also help you sleep better and reduce anxiety.

Acupuncture This ancient Chinese practice is sometimes used to relieve psoriasis symptoms. Scientific research about its effectiveness has been inconclusive, but patients report that it can offer relief.